1. Technical Field of the Invention
The present invention pertains to the field of hand and power tools and, in particular, to multiple-head tools such as a multiple-head screwdriver.
2. Discussion of the Prior Art
Most people perform repairs in and about their house or apartment or build various implements such as desks, cabinets and so forth for use in and about their home or apartment. As these people can attest, there are many occasions when they need to use tools such as screwdrivers which have several different types of heads--such as "flat-head" screwdrivers, "phillips-head" screwdrivers, "robertson-head" screwdrivers, "hex-head" screwdrivers and so forth--as well as tools such as screwdrivers which have several different sizes of a particular type of head.
A common method of satisfying the above-identified need for using tools having several different types of heads has been to provide a multiplicity of different types of heads of a multiplicity of different sizes which can individually be fitted into a chuck in a handle. Such a solution has proved to be unsatisfactory for the primary reason that one constantly misplaces heads while working and, worse, one loses heads permanently. Further, another drawback of this common solution is that one often finds it difficult to change heads while working because the heads are often not conveniently at hand.
Another method of satisfying the above-identified need for using tools having several different types of heads has been to provide a multiple-head tool. Such a solution has proved unsatisfactory because such tools do not include a means for holding and steadying the head of the tool with one hand --without changing position the grip of the one hand--while applying torque to the handle of the tool with the other hand. In addition, such tools do not provide protection from electric shock when the tools are used around electrical wires, especially when the head is gripped to steady the aim and/or to improve the stability of the screwdriver when in use.
There have been many other attempts in the prior art to solve the above-identified need but they have all been unsatisfactory for one reason or another. For example, some such attempts pertaining to the first type of solution discussed above are found in U.S. Pat. Nos. 3,799,226, 4,328,721, 4,463,788, 4,476,751, and 4,488,462 and some such attempts pertaining to the second type of solution discussed above are found in U.S. Pat. Nos. 385,791, 750,182, 910,789, 966,529, 1,616,300, 2,629,415, 3,014,388, 4,512,693, 4,590,824, 4,774,736.
U.S. Pat. No. 3,799,226 issued on Mar. 26, 1974 discloses a screwdriver having a multiplicity of individual heads. The heads are rotatably mounted within a blade holder. The blades may be rotated to a first position for use or rotated to a second position for storage in a chamber in a handle. The disclosed screwdriver has several drawbacks. A first drawback is that there is no means for holding and steadying the head with one hand while applying torque to the handle with the other hand. A second drawback is that there is no protection from electric shock when it is used around electrical wires, especially when the head is gripped to steady the aim and/or to improve the stability of the screwdriver when in use. A third drawback is that the disclosed screwdriver is complex and, therefore, expensive to manufacture.
U.S. Pat. No. 4,328,721 issued on May 11, 1982 discloses a phillips-head screwdriver having a retractable slotted blade which forms a flat-head screwdriver. The phillips-head and the fIat-head are interchanged by means of a twist-lock mechanism and a lever or button. The disclosed screwdriver suffers from the drawback that it only has two heads, i.e., a single sized phillips-head and a single sized flat-head, in addition to the drawbacks discussed above with respect to the screwdriver disclosed in U.S. Pat. No. 3,799,226.
U.S. Pat. No. 4,463,788 issued on Aug. 7, 1984 discloses a screwdriver having a multiplicity of heads which are stored in a handle. The heads may individually be inserted into position for use without being detached from the screwdriver. The disclosed screwdriver has several drawbacks which are similar to the drawbacks discussed above with respect to the screwdriver disclosed in U.S. Pat. No. 3,799,226.
U.S. Pat. No. 4,476,751 issued on Oct. 16, 1984 discloses a screwdriver having a multiplicity of independent heads. The heads are each independently rotatably mounted at one end of a handle. Each head can be rotated for storage along the handle or rotated to extend outward from the handle for use. The disclosed screwdriver has several drawbacks which are similar to the drawbacks discussed above with respect to the screwdriver disclosed in U.S. Pat. No. 3,799,226.
U.S. Pat. No. 4,488,462 issued on Dec. 18, 1984 discloses a screwdriver having a phillips-head and a flat-head. The disclosed screwdriver suffers from the drawback that it only has two heads, i.e., a single sized phillips-head and a single sized flat-head, in addition to the drawbacks discussed above with respect to the screwdriver disclosed in U.S. Pat. No. 3,799,226.
In addition, there have been other attempts at solving the above-stated problem in which a multiplicity of different heads are each rotatably affixed to a handle in close proximity to each other. These attempts have failed because, in general, they are awkward to use, are unnecessarily bulky, and are fabricated from metal so that one must take special precautions when handling them around electricity.
U.S. Pat. No. 385,791 discloses a tool which combines in one structure, a bit (or gimlet), a countersink (or reamer), and a screwdriver. The disclosed tool suffers from the drawbacks that there is no means for holding and steadying the head with one hand while applying torque to the handle with the other hand; there is no protection from electric shock when it is used around electrical wires, especially when the head is gripped to steady the aim and/or to improve the stability of the screwdriver when in use; and the disclosed screwdriver is complex and, therefore, expensive to manufacture.
U.S. Pat. No. 750,182 discloses a screwdriver with a reversible head. The tool suffers from the drawbacks discussed above with respect to the tool disclosed in U.S. Pat. No. 385,791.
U.S. Pat. No. 910,789 discloses a multiple-headed tool comprised of, for example, a multiplicity of watch-makers' tools of different sizes. Further, the tools which are not used are covered by a smooth shield. The tool suffers from the drawback that, although the shield may be grasped to steady the tool and help in applying torque, the shape of the shield is such that one cannot maintain contact with the shield without changing the position of the hand that grasps it. Further, because the disclosed tool is to be used for purposes of repairing watches, there is no disclosure of a protection from electricity. Lastly, the mechanism for fixing a tool in place for use is complex and, therefore, expensive to manufacture.
U.S. Pat. No. 966,529 discloses a mulitple-headed tool comprised of, for example, a multiplicity of watchmakers' key elements. The tool suffers from the drawback that there is no means for holding and steadying the head with one hand while applying torque to the handle with the other hand. Further, because the disclosed tool is to be used for purposes of repairing watches, there is no disclosure of a protection from electricity. Lastly, the mechanism for fixing a tool in place for use is complex and, therefore, expensive to manufacture.
U.S. Pat. No. 1,616,300 discloses a screwdriver with a reversible head which is pivotally mounted in a slot at one end of a shaft. The other end of the shaft is inserted into a handle. A ferrule is slidably mounted on the shaft and is adapted to hold the reversible head at the forward end of the shaft in an operative position. In addition, the ferrule has a notch cut in each end and a pin so that the ferrule may engage the bit in the groove so that the head can be disposed at an oblique or at a right angle to the shaft. The disclosed tool suffers from the drawbacks that there is no means for holding and steadying the head with one hand while applying torque to the handle with the other hand and there is no protection from electric shock when it is used around electrical wires, especially when the head is gripped to steady the aim and/or to improve the stability of the screwdriver when in use.
U.S. Pat. No. 2,629,415 discloses a double edged screwdriver having a reversible handle. The screwdriver has opposed working edges disposed at opposite ends of the shank. The tool suffers from the drawbacks discussed above with respect to the tool disclosed in U.S. Pat. No. 385,791.
U.S. Pat. No. 3,014,388 discloses a multiple-headed tool comprised of, for example, a multiplicity of screwdrivers, Allen wrenches, socket wrenches, and so forth of varying sizes. The tool suffers from the drawbacks discussed above with respect to the tool disclosed in U.S. Pat. No. 385,791.
U.S. Pat. No. 4,512,693 discloses a reversible drill and drive tool holder. The tool suffers from the drawbacks discussed above with respect to the tool disclosed in U.S. Pat. No. 385,791.
U.S. Pat. No. 4,590,824 discloses a reversible bladed screwdriver. The tool suffers from the drawbacks discussed above with respect to the tool disclosed in U.S. Pat. No. 385,791.
U.S. Pat. No. 4,774,736 discloses a tool for skateboards which has a pair of oppositely disposed screwdriver heads disposed at one end. The disclosed tool suffers from the drawbacks that there is no means for holding and steadying the head with one hand while applying torque to the handle with the other hand; and there is no protection from electric shock when it is used around electrical wires, especially when the head is gripped to steady the aim and/or to improve the stability of the screwdriver when in use.
As one can readily appreciate from the above, there exists a need in the art for a multiple-head tool such as a multiple-head screwdriver which has: (1) a multiplicity of heads of varying head type and/or varying head size in a single unit to provide ready access thereto to prevent loss of heads and (2) means for holding and supporting the head with one hand while the other hand supplies torque to rotate the head, which means protects against electric shock.